33892-95-4Relevant articles and documents
TRIVALENT PHOSPHOROUS ACID IMIDAZOLIDES
Grachev, M. K.,Iorish, V. Yu.,Bekker, A. R.,Nifant'ev, E. E.
, p. 57 - 62 (2007/10/02)
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KINETIC STUDY OF THE HORNER-REACTION. I
Larsen, Rolf Olaf,Aksnes, Gunnar
, p. 219 - 228 (2007/10/02)
The rates of the Horner-reaction of five phosphonates (I-V) with sodium ethoxide and various p- and m-substituted benzaldehydes, and ethanol as solvent, are reported.The kinetics of the reactions are overall third order, first order in phosphonate, ethoxide, and aldehyde, respectively.The reaction is accelerated by electron-withdrawing substituents in the benzaldehyde, giving a reaction constant, ρ, of approximately +2.0.The five-membered cyclic phosphonate (IV) is found to react about 20 times faster than its acyclic analogue (I).The rate difference is attributed to a considerable release in ring strain upon passing from the tetrahedral to the pentacoordinate state in the intermediate of the cyclic phosphonate.